Shutting down Linux servers

This topic discusses the multiple methods to shut down integrated Linux^® servers.

Just as starting Linux servers can be accomplished in multiple ways, so can stopping Linux servers. In this section we cover ways to shut down Linux servers, and unique situations that arise in an integrated environment.

You must shut down your Linux servers before performing i5/OS™ system tasks such as:

Backing up statically linked storage spaces. Statically linked storage spaces can only be backed up when Linux servers are shut down.
Putting an i5/OS partition into restricted state. When you end i5/OS to restricted state, the iSeries™ can only be accessed through the console. If you put your iSeries into restricted state by ending all subsystems immediately, your integrated Linux servers are not automatically shut down. Because you normally put i5/OS into restricted state to perform a backup, you need to shut down the Linux servers in order to back up their components. If a server is running, components such as storage spaces are locked, and excluded from the back up. Therefore, you should shut down your integrated servers in a controlled manner before putting i5/OS into restricted state.
Performing a complete system backup. Performing a complete system save using option 21 on the Save menu is an easy way to ensure that you have a complete backup of your iSeries system, including your integrated Linux servers. Option 21 on the Save menu has an option that allows you to automatically shut down integrated servers before starting a backup. To set this option:
1. Type go save on the i5/OS command line. Press Enter.
2. Type 21, press Enter.
3. You see the Save the Entire System display. Press Enter.
4. On the Specify Command Defaults display there is an option called “Vary off network servers”. This option defaults to *NONE, which does not shut down integrated servers. To ensure that integrated Linux servers are shut down before the backup starts, specify *ALL.
5. Fill out the other options. Press Enter to start the backup.
Powering down the iSeries. It is strongly recommend that you shut down your servers in a controlled manner before powering down the iSeries using the Power Down System (PWRDWNSYS) command.

Important: Always shut down your integrated Linux servers before you put i5/OS into restricted state, and prior to powering down the iSeries. Otherwise you might lose data or corrupt the Linux operating system.

Shut down a single Linux server using iSeries Navigator

To shut down a single Linux server using iSeries Navigator:

Click Servers under Integrated Server Administration.
Right-click the server you wish to shut down.
Select Shut Down or Shut Down and Restart.
You see a shut down confirmation window. Click Shut Down.

After a few moments you should see the server status change to Shutting down. The status automatically changes to Shut down when the server is completely shut down. You do not need to refresh the window.

Shut down multiple Linux servers using iSeries Navigator

To shut down all integrated servers simultaneously select one of the following methods:

Right-click Servers in the left pane and select Shut down all.
Click Shut down all integrated servers in the Taskpad pane.

To shut down selected servers simultaneously, hold down the control key (Ctrl) and click each of the servers you want shut down. Then right-click one of the selected servers and click Shut down.

Because of interdependencies between servers, you might wish to shut down the servers in a specific order. If you want to do this automatically, see Shut down a single Linux servers using CL commands.

Shut down a single Linux servers using CL commands

To shut down a single Linux server from an i5/OS command line, select one of the following CL commands.

WRKCFGSTS

1. Type WRKCFGSTS *NWS. Press Enter.
Type 2 in the Opt column next to the network server description (NWSD) that you want to vary off. Press Enter.

To shut down multiple Linux servers using the WRKCFGSTS command, simply type 2 in the Opt column next to all the network server descriptions (NWSDs) that you want to vary off. Press Enter.

VRYCFG

Type VRYCFG. Press F4.
Enter the following parameters:
- The NWSD that you want to vary off.
- The status: *OFF.
Press Enter.

Here is an example:

VRYCFG CFGOBJ(nwsd-name) CFGTYPE(*NWS) STATUS(*OFF)

To shut down multiple Linux servers using the VRYCFG command, simply list all the network server descriptions (NWSDs) that you want to vary off in the CFGOBJ parameter. Press Enter. For example:

VRYCFG CFGOBJ(nwsd-name1 nwsd-name2 nwsd-name3) CFGTYPE(*NWS) STATUS(*OFF)

Shut down Linux servers from the Linux console

Every Linux server can be shut down from the Linux console by entering the command shutdown -h now. The Linux operating system shuts down but the NWSD is still considered to be varied on.

The WRKCFGSTS command shows the NWSD with a status of SHUTDOWN, and the status of the communications objects under it are FAILED. This is normal for servers that are shut down from the console. On the WRKCFGSTS *NWS display you can enter a 2 next to the NWSD to complete the vary off.

You can also shut down and restart an integrated Linux server from the console by entering the appropriate command. You often need to restart the server after installing new software or reconfiguring the operating system. In this case you do not need to restart Linux from the i5/OS side.

Shut down xSeries servers from the Linux console

Shutting down a Linux server that is running on an Integrated xSeries^® Adapter-attached xSeries from the Linux console is a special case. In this case you should not shut Linux down through the Linux console. The reason for this is that when you shut down an integrated Linux server in this way, the xSeries server is turned off completely. This causes the Integrated xSeries Adapter to lose power and stop communicating over the HSL loop. The System Licensed Internal Code (SLIC) on the iSeries interprets this as one of its towers (the Integrated xSeries Adapter-attached xSeries in this case) having been turned off, and removed from the HSL loop. The iSeries goes into HSL recovery. The other iSeries towers in the loop should remain unaffected because data flows both ways around the loop, and the other towers still have a connection to the iSeries system unit. But if multiple Integrated xSeries Adapter-based integrated servers are shut down from the Linux console, towers that are cabled between the shut down servers on the HSL loop become isolated and no longer have a connection to the iSeries system unit. If the isolated towers contain disk units, the iSeries terminates abnormally. Also, if the loop contains a migration tower, shutting down a single Integrated xSeries Adapter-based server from the console can also bring down the iSeries because data can only flow one way around the HSL loop to a migration tower.

For integrated Linux servers running on Integrated xSeries Adapter-attached xSeries machines, the correct way to shut down is from iSeries Navigator or the i5/OS command line.

For more information on HSL configuration, search for redp-3652 at the following Web site:

http://www.redbooks.ibm.com/ Link outside information center

Shut down Linux servers by forcing a shut down

When you issue a shut down command to an integrated Linux server from iSeries Navigator or an i5/OS command line, the shut down command is passed to the server to enable it to shut itself down cleanly. By default, i5/OS waits 15 minutes (900 seconds) before it performs a forced shut down of an integrated Linux server if the server has not already shut itself down. If you want to change this default value, do the following steps:

Shut down the Linux server.
On an i5/OS command line enter the Change Network Server Description (CHGNWSD) command and press F4.
Scroll down to the Shutdown time-out (SHUTDTIMO) parameter and enter the new default value. Press Enter.
Restart the server.

Shut down Linux servers by powering down the iSeries

It is strongly recommended that you do not power down your i5/OS partition when Linux servers are active. When the Power Down System (PWRDWNSYS) *IMMED command is issued, i5/OS does not try to shut down any active integrated Linux servers. When the iSeries powers down it cuts power to the Linux servers. There is a possibility of data corruption if the servers suffer a forced shut down in this way. Always shut down your Linux servers cleanly prior to issuing the PWRDWNSYS command.

Note: The Power Down System (PWRDWNSYS) *CNTRLD command will attempt to vary off any active servers prior to powering down the system.

Important: Never issue a PWRDWNSYS *IMMED command without having your integrated Linux servers in shutdown status.